Dry separator.



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C. HERING.

`DRY SBPARATOR.

APPLIOATION FILED Nov. fr. 190e.

Patented Oct. 17, 1911.

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UNITED @BATES PATENT OFFICE.

CARL HERING, OF PHILADELPHIA, PENNSYLVANIA.

DRY SEPARATOR.

To all whom it may concern.'

Be it known that I, CARL HERING, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements in DrySepa.- rators, of which the following is a specification.

rlhe object of this invention is to provide an apparatus for separatingmixtures of particles, as for instance ores of'different specificgravities, by subjecting the particles to a current of air while theyare in motion or are free to move. In the preferred form of theinvention this is accomplished by passing a substantially horizontalcurrent of air over the particles while they are rolling slowly down alarge number of short inclined planes, alternating with short falls.

When a thin layer comprising a mixture of particles is shaken on a flatboard and subjected to a current of air, the lighter particles are blownover the heavier ones and a certain separation is accomplished. In orderthat the separation may be effective the particles should all be capableof moving with freedom over each other, and they should have a movementof their own transverse or nearly so to the direction of the aircurrent, in order that they may pass into different bins. Even in suchcase it is found that when the air current is suiliciently strong toproduce a separation, it tends to blow the small particles of relativelyhigh specific gravity away with the large particles of relatively lowspecific gravity, thus necessitating a more or less accurate sizingbefore concentration or a loss of the line material of high speciiicgravity. It is also found that the flat or flaky particles, eventhoughof high specilic gravity, are apt to be blown away with the light ones,and this cannot be avoided by sizing. When the movement of the particlesis produced by rolling them down a smooth plane, those light particleswhich are round are apt to acquire such velocity that the air currenthas little effect on them, and they therefore pass oli with the heavyparticles.

. I have found that the above objections f vmay be overcome bysubjecting the particles while in motion or free to move to a current 1of air. of relatively low velocity but acting Specification of LettersPatent.

Application filed November 7, 1906.

ration.

Patented Oct. 17, 1911.

Serial No. 342,397.

:angle of repose is meant the steepest slope to which granular materialmay be heaped without rolling down to theV base. When vparticles arerolled down over themselves at this angle they generally tend to formlwhat may be called avalanches, thaty is, theywill pile up to a greaterangle and then a mass of them will break olf and slide down together;this tendency I overcome by making the slopes very short and providing alarge number of them, alternating with `short falls from one to thenext. I find also that the line particles of relatively high specificgravity will then settle down on the rough surface where they aresheltered somewhat from the air current, and that the large, lightparticles being subjected to the full force of the air will then rollmore freely over them, thereby producing a sepa- This is important, asthe tendency is to blow the heavy, fine material out wit-h the lighteras above stated. By this means therefore I avoid the necessity ofaccurate sizing and of concentrating each size separately. Theseparation of the heavy, fine particles from the coarse, light ones maybe further aided by diminishing the air currents over those parts of thebed where the mixture of these classes of particles tend to pass, aswill be hereinafter explained. I also avoid the necessity of using anyshaking or percussion mechanism, and am therefore enabled to make theinclined plane as large and long as maybe desirable; no moving partsexcept the feeding mechanism and the apparatus for producing aircurrents are required.

For a full understanding of the invention reference is made to theaccompanying drawing wherein:

Figure l is a vertical section through a preferred form of separator;Fig. 2 is a face view of the same, the cover plate being removed; Figs.3, 4, 5 illustrate various forms and constructions of grooves which maybe employed; and Fig. 6 is a transverse section showing a modied form ofcover plate.

Referring to the drawings, 1 represents an inclined bed or support, theupper surface of which is provided with parallel and substantiallyhorizontal grooves or corrugations: as shown the grooves 3 are formed ina sheet 2 carried by the support 1, the construction of the apparatus inthis respect being however immaterial. The inclination of the bed 1should somewhat exceed the angle of repose of the material, as indicatedin Fig. 3, wherein the dotted line a-a indicates the angle of repose,and b-b the inclination of the grooved bed. The apparatus is operativeover a considerable range of inclinations, but the angle of inclinationshould in all cases be greater than the angle of repose of the materialto be separated, and the grooves should be adapted to retain some of thematerial. In the form. of apparatus shown the material is fed to the topof the bed at one side thereof through a hopper L1 having a groovedfeed-roller 5, and is discharged from substantially the entire width ofthe bed by a grooved roller 6, the particles being delivered to an apron7 and passing thence to the various hoppers or bins 8, 9, 10, 11. Theair current is confined by a cover plate 12, the portion of which remotefrom the line of feed is preferably flared upwardly as indicated at 13,Figs. 1 and 6. The purpose of the cover 12 and of the rollers 5, 6 is toprovide an approximately air-tight casing for the bed for confining theair current to the vicinity of the particles to be separated.

The operation of the device as above described is as follows: The mixedparticles are supplied to the upper portion of the bed at one sidethereof from the hopper l, and subjected thereon to an air currentsubstantially parallel to the grooves and therefore transverse to thegeneral direction of movement of the particles. The grooves retaining acertain quantity of the material, there will be formed a large number ofsmall inclinations 14, made by the material itself, over which the restof the material will roll slowly. At the end of each small ineline, theparticles will fall to the next, and during these short falls they willacquire only a very small velocity and will therefore be deflected to agreater extent by the air current. The manner in which material fed fromthe hopper 4c tends to be separated during its downward movement isindicated by the dotted lines in Fig. 2; in practice it may sometimes bepreferable to make the inclined bed shorter and to pass the middlingsthrough the same or a similar separator.

In order to prevent the air current from blowing the material out of thegrooves, these may be made relatively deep as shown in Fig. 4; or thebottoms of the grooves may be roughened by cementing sand therein or byother means as indicated at 15 in Fig. 5. After the grooves are oncefilled the air current does not blow out the material.

I prefer to use suction rather than pressure for establishing the aircurrent. The apparatus is then dustless, and the dust is more easilycollected in the usual bags; moreover the front edge of the inclined airchannel is then always open for inspection. Suction applied at the sideof the bed where the lighter particles tend to pass also enables a moreuniform air current to be established over the whole surface, and thecurrent is more free from eddies.

In order to render still more eective the separation of the fine, heavyparticles from the coarse, light ones, and to prevent any considerableproportion of the ne, light material from being drawn into the dustbags, I prefer to Hare the cover plate as shown at 13 in Figs. 1 and 6,making the air channel relatively small in cross sectional area over theparts where the heavy particles pass down, and relatively large over thepath of the lighter particles. Thus the air current will have itshighest velocity over the heavy particles and will gradually diminish invelocity toward the other side of the bed, thereby depositing thelighter particles which are apt to be floated by the air, and causingthem to roll down under the best conditions for separation.

Instead of a steady current of air I may use a variable or intermittentair current or pu`s of air. Such variations or pus may be produced inthe blower by the disposition of the blades therein or in any otherconvenient way; for instance in Fig. 6 I have shown a rotary fan orblower 16 connected to the suction side of the casing, and provided witha single blade 17, the eect being the production of an intermittent aircurrent or one of variable velocity. Or I may approximate the effect ofpuffs by corrugating the upper side of the air channel perpendicularlyto the direction of the air current, as shown at 18 in Fig. 6. A steadyair current will thereby be converted into one having alternatelygreater and less velocity as it passes through the contracted andwidened channels produced by these corrugations. rIhus any smallerparticles which may have floated will have opportunities to settle.

While the concentrator will operate without any movement of the inclinedbed, it may at times be desirable, as for instance for the finest dust,to slightly shake or tap the bed. This may be effected by a simplearrangement, as indicated at 19 in Fig. 1. As the operation of theapparatus is sensitive to variations of the air current, I may connect apressure gage to any convenient part of the channel as shown forinstance at 20 in Figs. land 3, as an aid in keep-ing the pressureconstant and in producing the same pressure at any future time.

The grooves should be adapted to the character of the mixture to beseparated, and in general the grooves should be narrower for finergrained materials and wider for coarser mixtures.

An advantage of this apparatus is that the separated materials pass fromthe concentrator in the form of a continuous stream of particles alongthe whole of the lower edge, varying with more or less pronouncedgradations from the best concentrates at the one side to the besttailings at the other, with the middlings between them; it is thereforewithin the easy control of the operator to divide this stream intoconcentrates, middlings and tailings at any two points desired, therebyobtaining concentrates of any desired richness, tailings of any desiredleanness, and correspondingly larger or smaller amounts of middlingswhich are again separated.

A further advantage of the apparatus is that mixtures of three or morematerials may be separated in the same device.

I claim:

l. Apparatus for separating mixtures comprising an imperforate inclinedbed, grooves thereon disposed transversely to the direction ofinclination of the bed, means for feeding material to the higher portionof the bed, and means for establishing an air current above said bedlongitudinally of said grooves.

2. Apparatus for separating mixtures comprising an imperforate inclinedbed, the inclination of the bed exceeding the angle of repose of theparticles, grooves thereon disposed transversely to the direction ofinclination of the bed, means for feeding material to the higher portionof the bed, and means for establishing an air current above said bedlongitudinally of said grooves.

3. Apparatus for separating mixtures comprising an imperforate inclinedbed, grooves thereon disposed transversely to the direction ofinclination of the bed and adapted to retain portions of the mixture inthe form of separate parallel bodies having surfaces at their angle ofrepose, means for feeding ma# terial to the higher portion of the bed,and means for establishing an air current above said bed longitudinallyof said grooves.

t. Apparatus for separating mixtures comprising an imperforate inclinedbed, grooves thereon disposed transversely to the direction ofinclination of the bed, a casing providing a confined space `above saidbed, means for feeding material to the higher portion of the bed, andmeans for establishing an air current above said bed longitudi nally ofsaid grooves.

5. Apparatus for separating mixtures comprising a bed inclined in thedirection of delivery of the particles and provided with means forretarding the downward movement of particles thereon, a casing providinga confined space above said bed, substantially air-tight feed anddischarge devices for said casing, and means for establishing atransverse air current through said casing.

6. Apparatus for separating mixtures comprising a bed inclined in thedirection of den livery of the particles and provided with means forretarding the downward movement of particles thereon, means for feedingmateriai to the upper portion of said bed, a casing providing a confinedair space above said bed and flaring outwardly in the direction of thetransverse air current above a portion thereof, and means forestablishing a transverse air current through said casing.

7. Apparatus for sep arating mixtures comprising an imperforate inclinedbed, means for feeding material to the higher portion of the bed, meansupon the surface of the bed for retarding the downward movement of theparticles, means for establishing a transverse air current above saidbed and substantially parallel to the surface thereof, and means forvarying the velocity of said air current over portions of the bed.

8. Apparatus for separating mixtures comprising an imperforate inclinedbed, means for feeding material to the higher portion of the bed nearone side thereof, means upon the surface of the bed for retarding thedownward movement of the particles, means for establishing a transverseair current above said bed and substantially parallel to the surfacethereof, and means for reducing the velocity of the air current over theside of the bed remote from said feeding means.

9. Apparatus for separating mixtures comprising a bed inclined in thedirection of delivery of the particles and provided with means forretarding the downward movement of particles thereon, means for feedingmaterial to the upper portion of said bed, a casing providing a confinedspace above said bed and provided with longitudinal recesses, and meansfor establishing a transverse air current through said casing.

10. Apparatus" for separating mixtures comprising an imperforateinclined bed, means for feeding material to the higher portion of thebed, means upon the surface of the bed for retarding the downwardmovement of the particles, and means for establishing a transverse aircurrent of vary ing velocity above said bed and substantially parallelto the surface thereof.

11. Apparatus for separating mixtures comprising an imperforate bedarranged at an inclination greater than the angle of repose of themixture delivered thereto, means tudinally of said parallel bodies andsubl0 for retaining on said bed a portion of the stantially parallel tothe surface of the bed. mixture in the form of separate parallel Intestimony whereof, I afx my signature plodies disposed transilersely of1thefbed and in presence of two witnesses.

avmg surfaces at t eir ang e o repose, means for feeding material to theupper por- CARL HERING' tion of said bed and discharging it from theWitnesses: lower portion thereof, and means for estab- VIOLA E. IRWIN,lishing an air current above said bed longi- WALTER E. WEYL.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

